SWODY2
SPC AC 161721
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1221 PM CDT SUN MAR 16 2008
VALID 171200Z - 181200Z
..THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS AND OZARK PLATEAU...
..SRN PLAINS...
A HIGHLY MERIDIONAL UPPER-LEVEL TROUGH AND CLOSED-LOW OVER THE SWRN
STATES IS FORECAST TO MOVE INTO THE FOUR CORNERS REGION TONIGHT AND
INTO THE SRN ROCKIES MONDAY. IN RESPONSE...A 60 KT LOW-LEVEL JET
WILL STRENGTHEN OVER THE SRN PLAINS TONIGHT QUICKLY TRANSPORTING
LOW-LEVEL MOISTURE NWD INTO NORTH TX AND OK. DUE TO WARM ADVECTION
AND COLD AIR ALOFT...A CLUSTER OF THUNDERSTORMS WITH HAIL POTENTIAL
MAY BE ONGOING AT THE BEGINNING OF THE PERIOD ACROSS NORTH TX AND
OK. AS THE UPPER-LEVEL SYSTEM APPROACHES THE HIGH PLAINS MONDAY...A
DRYLINE WILL ORGANIZE FROM NCNTRL TX EXTENDING SSWWD INTO SOUTHWEST
TX. MODEL FORECASTS ARE CONSISTENT WITH ACTIVATING THE DRYLINE
ACROSS WCNTRL TX AND OK WITH THE DEVELOPMENT OF NUMEROUS
THUNDERSTORMS BY SUNDAY EVENING.
CONCERNING THE SHEAR ENVIRONMENT...MODEL FORECASTS MONDAY AND MONDAY
NIGHT ESTABLISH STRONG MID-LEVEL FLOW ACROSS THE SRN PLAINS
RESULTING IN 50 TO 60 KT OF VERTICAL SHEAR. THIS COMBINED WITH
MODERATE DESTABILIZATION ALONG THE RETREATING DRYLINE SHOULD RESULT
IN THE INITIATION OF NUMEROUS SEVERE STORMS. ALTHOUGH THE DOMINANT
MODE OF CONVECTION DURING THE EVENT REMAINS UNCERTAIN...IT APPEARS
THE SUPERCELL THREAT WILL BE QUITE HIGH DURING THE FIRST PART OF THE
EVENT EARLY MONDAY EVENING. THE STRONG VERTICAL SHEAR AND STEEP
MID-LEVEL LAPSE RATES SHOULD BE VERY FAVORABLE FOR LARGE HAIL AND
HAILSTONES GREATER THAN 2 INCHES WILL BE POSSIBLE. IN
ADDITION...FORECAST SOUNDINGS ALONG THE DRYLINE INCREASE LOW-LEVEL
SHEAR PROFILES BY EARLY EVENING WITH GRADUAL VEERING AND STRONG
SPEED SHEAR IN THE LOWEST 2 KM SUGGESTING THE SHEAR ENVIRONMENT WILL
BE FAVORABLE FOR TORNADOES. IF DISCRETE SUPERCELLS PERSIST DURING
THE EVENING...AN ISOLATED THREAT FOR STRONG TORNADOES MAY ALSO
DEVELOP IN A NARROW CORRIDOR ACROSS THE TX HILL COUNTRY INTO NCNTRL
TX. CONCERNING CONVECTIVE MODE...A TRANSITION TO A MORE LINEAR
STRUCTURED MCS MAY OCCUR DURING THE LATE EVENING AND OVERNIGHT
PERIOD. FORECAST SOUNDINGS MONDAY NIGHT SUGGEST SHEAR AND
INSTABILITY WILL BE SUFFICIENT TO CONTINUE A SEVERE THREAT WITH
LARGE HAIL AND ISOLATED WIND DAMAGE BEING THE PRIMARY THREAT AFTER
06Z TUESDAY.
..OZARK PLATEAU/CNTRL PLAINS...
AN UPPER-LEVEL LOW WILL MOVE INTO THE ROCKIES SUNDAY NIGHT INTO
MONDAY AS THE EXIT REGION OF A 60 KT LOW-LEVEL JET MOVES ACROSS THE
CNTRL PLAINS AND OZARK REGION. COLD AIR ALOFT AND STRONG WARM
ADVECTION ASSOCIATED WITH THE LOW-LEVEL JET MAY SUPPORT A MARGINAL
HAIL THREAT MONDAY MORNING. AS THE TROUGH APPROACHES THE HIGH PLAINS
MONDAY AFTERNOON...A SFC LOW WILL ORGANIZE AND MOVE QUICKLY NEWD
ACROSS KS INTO MO MONDAY NIGHT. SFC DEWPOINTS EAST OF THE LOW SHOULD
INCREASE INTO THE LOWER 60S F AS CONVECTION INITIATES ALONG AND JUST
AHEAD OF A COLD FRONT MONDAY EVENING.
CONCERNING THE SEVERE POTENTIAL...VERY STRONG VERTICAL SHEAR IS
FORECAST TO BE IN PLACE ACROSS THE REGION AS A 80 TO 90 KT MID-LEVEL
JET EJECTS NEWD ACROSS THE CNTRL PLAINS AFTER 06Z TUESDAY. EVEN
THOUGH INSTABILITY MAY BE SOMEWHAT LIMITED IN KS AND MO...FORECAST
SOUNDINGS SHOW SUFFICIENT ELEVATED INSTABILITY...SHEAR AND COLD AIR
ALOFT TO SUPPORT A THREAT FOR HAIL.
.BROYLES.. 03/16/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment